When using an analysis device for analyzing a medically significant component of a bodily fluid, such as blood or interstitial liquid, a qualitative or quantitative analysis is performed, i.e., for example, the presence, the absence, or the concentration of a specific analyte in a sample is determined. Exemplary known devices comprise a portable analysis device, operable by a patient for patient self-testing. Typical devices are configured for analysis or measurement of blood glucose, cholesterol, and blood coagulation parameters.
Analysis devices of this type comprise a device housing, a measuring unit situated in the device housing for performing the analysis on a sample, and a processor having software for processing the measured values ascertained by the measuring unit and for preparing the analysis measurement data from the measured values, typically taking into account calibration values. For example, the sample may be applied to a test element, such as a test strip, which is inserted through an opening in the housing of the analysis device and thereby into contact with the measuring unit. In other embodiments, analysis devices are also known in which sample (or more particularly a the test element wetted by a sample) is exposed to or contacted by a measuring sensor, which is located in the analysis device or projects therefrom. The use of magazines for test elements is also known in this context.
Test methods which work with test elements are typically used to a large extent for qualitative and/or quantitative analysis of components of a liquid sample, in particular a bodily fluid of humans or animals. The test elements typically contain reagents configured to react with the liquid sample or analytes therein. For example, to perform a reaction, the test element is brought into contact with the sample. The reaction of sample and reagents results in a change of the test element characteristic for the analyte, which characteristic is analyzed with the aid of the analysis device. The analysis device is typically capable of analyzing a very specific type of test element of a specific manufacturer. That is, the test elements and the analysis device typically form components mutually tailored to one another and are referred to as a whole as an analysis system.
Numerous different test element types are known, which differ in the measurement principle and the reagents used and in their construction.
Colorimetric analysis systems are an example of the use of one type of measurement principle. In such a system, the reaction of the sample with the reagents contained in the test element results in a color change therein, which may be measured visually or using a photometric measuring unit. Alternatively, electrochemical analysis systems are an example of another popular type of measurement principle, in which the reaction of the sample with the reagents of the test element results in an electrically measurable change (of an electrical voltage, electrical charge or an electrical current), which is measured using corresponding measurement electronics. Analysis systems of this type include what are referred to as amperometric systems; that is, those in which the measurement principle comprises the measurement of current.
In the context of analysis devices for analysis or measurement of analytes in bodily fluids, regular monitoring of specific analytical values of the blood is frequently necessary. This is true in particular for diabetics, who are to check their blood sugar level frequently using blood sugar self-testing, to keep their blood sugar level continuously within specific setpoint limits as much as possible by adapting insulin injections to the greatly varying demand. Checking blood coagulation parameters through a patient blood coagulation self test is also correspondingly common.
A blood glucose measuring device is a measuring device, with the aid of which the blood sugar content may be determined qualitatively or quantitatively. For this purpose, a piercing wound is typically generated in a body, a blood droplet is taken, the blood droplet is applied to the test element, and the blood glucose content in the drop is determined with the aid of the test element and the blood glucose measuring device. However, measuring the blood glucose by a permanent measurement, for example, using sensors inserted into the body or through the skin, is also conceivable.
Above all in the field of so-called “home monitoring”, i.e., in which medical laypersons perform simple analyses of the blood themselves, and particularly therein for the regular blood acquisition to be performed multiple times daily by diabetics for checking the blood glucose concentration, it is important that simple and reliable operation of the blood glucose measuring device is possible and informative and reliable determination and display of the measurement results are provided.
The typical analysis devices are so-called standalone, portable measuring devices. These devices operate autonomously, self-contained, and independently. They thus typically comprise a display screen, a measuring unit, a power supply, and a user interface, which may comprise a keypad, a display, a signal generator, or a user guide, for example. The intended purpose and the properties of devices of this type are typically fixed, except for occasional adaptations of the firmware.
The present invention generally relates to the design and manufacture of analysis devices, and more particularly to the assembly of housing parts, as may be used for, e.g., blood sugar measuring devices. Typically, a housing for such a device comprises two parts, a housing upper shell and a housing lower shell. The housing also typically comprises operating elements within the surface of the housing, e.g., a keypad, pertaining to the particular device. During typical manufacture of a device, a functional check of the measuring device housed within the housing is performed after the two housing halves have been joined. This typically occurs as a last or near-final step in the assembly of the analysis device. Snap connections are frequently used according to the prior art to make the assembly of the housing halves as favorable as possible. Further disassembly of the housing halves which have been joined together in this way is usually not possible, because the assembly must meet the requirement of ensuring that the housing cannot be opened by the end-user (in order to protect the measurement device itself). Therefore, if flaws are discovered during the final functionality check, e.g., in the operating elements, then in order to repair the device, the housing must be opened, thereby destroying the housing halves.
In the past, analysis measuring devices have either been connected to one another by a screw connection or the housing parts are snapped together (as described above) in the final assembly step. Because it is important to ensure that it be recognizable whether a device has been previously opened, the typical snap connection is designed so that the mating components are destroyed upon reopening of the device. Also, if the housing is assembled using a screw connection, screws are normally covered by a seal, a label, or protective lacquer, which are designed so that the seal or label must be pulled off (which results in damage to the seal/label) or the protective lacquer on the screw must be obviously damaged when the device is opened.
After the assembly of a prior art analysis device, for example, from manufacture or after performing repair or maintenance, a final functionality test is typically performed. In order to do this, the device must be completely assembled. If a flaw becomes apparent at this point, the device must be disassembled again and repaired. The disadvantage of the screw connection and/or the nonremovable snap connection here is that after the disassembly, components may not be used again and increased costs thus occur. With a snap connection, the components having the snaps and/or snap receptacles are affected above all in this case. With parts which are screwed together, the reuse of the components having the screw bosses is critical. In addition, the use of screw connections increases the assembly effort and thus the costs.
Seals of containers or devices which prevent opening or allow only a single use of the device are known, for example, from the following publications: U.S. Pat. No. 3,753,586, U.S. Pat. No. 4,834,706, U.S. Pat. No. 4,875,486, U.S. Pat. No. 1,487,885, DE 4240327 C2, GB 984,593, GB 850,385, GB 2 040 267 A, U.S. Pat. No. 6,685,085 B2, WO 98/19723, US 2005/0227370 A1, U.S. Pat. No. 4,663,970, DE 27 53 285 A1, U.S. Pat. No. 2,772,109, U.S. Pat. No. 4,416,478, U.S. Pat. No. 2,142,048, FR 970,463, U.S. Pat. No. 2,081,627, U.S. Pat. No. 1,995,878, GB 1 475 543, all of which are hereby incorporated herein by reference in their entireties.